The chronic ingestion of alcoholic beverages has been demonstrated to be associated with an increased incidence of bacterial infections which are generally more severe in nature than in the non-alcoholic. These well known clinical observations denote the presence of as yet undefined alcohol-mediated alterations in host defense mechanisms. One goal of this research project is to define the basis of the alcohol mediated alterations in host defense mechanisms whereby increased proneness to infectious episodes is manifested during periods of alcohol abuse. Studies will be continued regarding the influence of acute and chronic ethanol ingestion, including the use of both laboratory ethanol and alcoholic beverages on functional expression of T and B lymphocytes and macrophages. Additional studies will be conducted employing vaporization techniques in which rats will be exposed to alcohol vapors to induce development of alcohol tolerance as well as possible liver dysfunction. The influence of prolonged ethanol exposure on macrophage and lymphocyte function, as well as induction of hepatic injury will ascertained in this model. Studies will also be conducted on status of humoral immunity as well as cell mediated immunity in animals maintained on chronic ethanol and alcohol beverage diets for a 21 day period of time. These studies will allow a comprehensive assessment of host defense mechanisms in the alcoholic and provide a possible explanation for increased incidence of infections in alcoholic subjects.